Ridha Joober

Prof. Ridha Joober


Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2012 in Journal of Psychiatry and Neuroscience
Verified
Journal Article
Closed access
RJRidha Joober
Ridha Joober
Norbert SchmitzNorbert Schmitz
Norbert Schmitz
LALawrence Annable
Lawrence Annable
PBPatricia Boksa
Patricia Boksa

6 December 2012 in BMC Psychiatry
Verified
Journal Article
Open access
PDF file
CHCindy L Hovington
Cindy L Hovington
MBMichael Bodnar
Michael Bodnar
RJRidha Joober
Ridha Joober
AMAshok K Malla
Ashok K Malla
MLMartin Lepage
Martin Lepage
Background: Although persistent negative symptoms (PNS) are known to contribute significantly to poor functional outcome, they remain poorly understood. We examined the heuristic value of various PNS definitions and their respective prevalence in patients with first episode psychosis (FEP). We also contrasted those definitions to the Proxy for the Deficit Syndrome (PDS) to identify deficit syndrome (DS) in the same FEP cohort. Methods: One hundred and fifty-eight FEP patients were separated into PNS and non-PNS groups based on ratings from the Scale for Assessment of Negative Symptoms (SANS). PNS was defined in the following ways: 1) having a score of 3 or greater on at least 1 global subscale of the SANS (PNS_1); 2) having a score of 3 or more on at least 2 global subscales of the SANS (PNS_2); and 3) having a score of 3 or more on a combination of specific SANS subscales and items (PNS_H). For all three definitions, symptoms had to be present for a minimum of six consecutive months. Negative symptoms were measured upon entry to the program and subsequently at 1,2,3,6,9 and 12 months. Functional outcome was quantified at first assessment and month 12. Results: PNS prevalence: PNS_1 (27%); PNS_2 (13.2%); PNS_H (13.2%). The prevalence of DS was found to be 3% when applying the PDS. Regardless of the definition being applied, when compared to non-PNS, patients in the PNS group were shown to have significantly worse functioning at month 12. All three PNS definitions showed similar associations with functional outcome at month 12. Conclusion: Persistent negative symptoms are present in about 27% of FEP patients with both affective and non-affective psychosis. Although there has previously been doubt as to whether PNS represents a separate subdomain of negative symptoms, the current study suggests that PNS may be more applicable to FEP when compared to DS. Although all three PNS definitions were comparable in predicting functional outcome, we suggest that the PNS definition employed is dependent on the clinical or research objective at hand.

30 November 2007 in Schizophrenia Research
Verified
Journal Article
Closed access
LBL Bechardevans
L Bechardevans
Norbert SchmitzNorbert Schmitz
Norbert Schmitz
SASherezad Abadi
Sherezad Abadi
RJRidha Joober
Ridha Joober
Suzanne KingSuzanne King
Suzanne King
AMAshok Malla
Ashok Malla

20 March 2013 in Obesity
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Journal Article
Open access
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ZCZia Choudhry
Zia Choudhry
SSSarojini M. Sengupta
Sarojini M. Sengupta
NGNatalie Grizenko
Natalie Grizenko
GTGeeta A. Thakur
Geeta A. Thakur
MFMarie‐Eve Fortier
Marie‐Eve Fortier
RJRidha Joober
Ridha Joober
Objective: Attention‐deficit/hyperactivity disorder (ADHD) is an etiologically complex heterogeneous behavioral disorder. Several studies have reported that ADHD subjects are more likely to be overweight/obese and that this comorbidity may be due to shared genetic factors. The objective of this study is to explore the association between ADHD and FTO, a gene strongly associated with obesity in genome‐wide studies.Design and Methods: One tag SNP (single‐nucleotide polymorphism, rs8050136, risk allele A) in the FTO gene was selected and its association with ADHD was tested. Family‐based association tests (FBATs) were conducted with the categorical diagnosis of ADHD as well as behavioral and cognitive phenotypes related to ADHD. Furthermore, stratified FBAT analyses based on maternal smoking during pregnancy (MSDP) status were conducted.Results: Statistically significant associations were observed between rs8050136 and several of the traits tested in the total sample. These associations were stronger when the analysis was restricted to children who were not exposed to MSDP.Conclusions: These exploratory results suggest the involvement of the FTO SNP rs8050136 in modulating the risk for ADHD, particularly in those children who were not exposed to MSDP. If confirmed, they may explain, at least in part, the complex links between obesity and ADHD.

16 March 2011 in European Archives of Psychiatry and Clinical Neuroscience
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Journal Article
Closed access
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OKOussama Kebir
Oussama Kebir
RJRidha Joober
Ridha Joober

1 August 2007 in SLEEP
Verified
Journal Article
Open access
PDF file
RGReut Gruber
Reut Gruber
NGNatalie Grizenko
Natalie Grizenko
GSGeorge Schwartz
George Schwartz
JBJohanne Bellingham
Johanne Bellingham
RGRosherrie Guzman
Rosherrie Guzman
RJRidha Joober
Ridha Joober
To examine whether the level of sleep efficiency of children diagnosed with ADHD moderates their performance on the Continuous Performance Test (CPT) while receiving a placebo and while receiving methylphenidate (MPH). Nightly sleep actigraphic assessment during a double-blind, placebo-controlled, crossover clinical study (1 week of 0.5 mg/kg MPH; 1 week of placebo) were obtained on 37 children between 6 and 12 years of age with a DSM-IV diagnosis of ADHD. Subjects were divided into 2 groups based on the mean sleep efficiency score during the placebo condition, with subjects above and below the mean placed in the Poor Sleep Group (PSG) and Good Sleep Group (GSG), respectively. Vigilance testing was conducted in the laboratory; sleep was assessed in the home. Sleep was monitored using actigraphy for 2 weeks. In addition, parents were asked to complete nightly sleep logs and a sleep questionnaire. The Conners' Continuous Performance Test (CPT) was used to assess vigilance. Significant interaction of Sleep Group with Medication was found on 1 CPT factor. The findings of the present study support the hypothesis that sleep moderates performance on CPT in children with ADHD while receiving placebo or MPH.